Mine hoist clutch



June 4, 1968 B. P. CLARKE MINE HOIST CLUTCH 3 Sheets-Sheet 1 Filed Jan.6, 1966 FIG.

INVENTOR BRUCE P. CLARKE BY W WTFM ATTORNEY B. P. CLARKE June 4, 1968MINE HOI ST CLUTCH 5 Sheets-Sheet 2 Filed Jan. 6, 1966 R 0 T N E V mBRUCE I? CLARKE ATTORNEY June 4, 1968 B CLARKE 3,386,549

MINE HOIST CLUTCH Filed Jan. 6, 1966 5 Sheets-Sheet 3 INVENTOR BRUCE I?CLARKE l2 BY 9 UTW ATTORNEY United States Patent 3,386,549 MINE HOISTCLUTCH Bruce P. Clarke, Lennoxville, Quebec, Canada, assignor toCanadian Ingersoll-Rand Company, Limited, Montreal, Quebec, Canada, aCanadian corporation Filed Jan. 6, 1966, Ser. No. 519,120 3 Claims. (Cl.192--71) ABSTRACT OF THE DISCLOSURE A clutch mechanism forinterconnecting a hoist drum to a drive shaft and including a radiallyslidable jaw block, a gear plate journalled on the drive shaft andcontaining an eccentric slot, a cam follower connected between theeccentric slot and the jaw block for moving the jaw block radially asthe gear plate is rotated on the drive shaft, and a drive motor forselectively rotating the gear plate relatively on the drive shaft.

This invention relates generally to clutch mechanisms and moreparticularly to clutch mechanisms of the type having internal expandingjaws for selectively providing a positive connection between a drivingmember and a driven member.

Briefly, this invention comprises a clutch mechanism for interconnectinga rotatable drive shaft to a drum or pulley for driving purposes. Theclutch mechanism includes a plurality of sliding jaws or blocks carriedby the drive shaft, which jaws may be selectively cammed into positivegripping engagement with means on the drum by a novel clutch operatingmechanism.

Prior clutch mechanisms of this general type were provided with slidablesleeve means which were longitudinally slidable on the drive shaft inorder to provide camming action for the axially movable jaws. Theseprior art mechanisms have proved to be inefficient and unsatisfactory inuse inasmuch as the sliding of the sleeve along the drive shaft resultsin excessive wear of the parts, and thus there is required expensiverepair and maintenance as well as frequent adjustments to themechanisms. These prior art mechanisms also required the outboardbearing for the drive shaft to be spaced from the shaft sufficiently toprovide room for the sliding movement of the sleeve means, thus reducingthe rigidity of the drive shaft and increasing the area occupied by thehoist.

Accordingly, it is an object of the instant invention to provide a novelclutch mechanism which substantially eliminates sliding motion betweenparts and hence, attendant wear and frequent adjustment, increases therigidity of the hoist drive shaft and reduces the area occupied by thehoist.

It is another object of the instant invention to provide a novel andunique camming mechanism for use in drum clutch mechanisms.

It is another object of the instant invention to provide an improvedclutch mechanism including electrically operated shut-off means for usetherewith.

These objects are attained, in brief, by the use of a rotatable platecontaining eccentric slots engaging levers for engaging and disengagingthe clutch jaws with the drum.

The invention will be more fully understood by reference to the drawingswhich illustrate a preferred embodiment of the invention and in whichsimilar reference characters refer to similar parts:

FIG. 1 is a perspective view of an end of a drum hoist containing theclutch mechanism of this invention;

FIG. 2 is an end elevational view of the hoist of FIG. 1; and

3,386,549 Patented June 4, 1968 FIG. 3 is a horizontal section and planview taken on the line 3-3 of FIG. 2.

Referring to the drawings, reference numeral 10 generally denotes a drumhoist including a hoist drum 12 having spokes 14 rotatably mounted on adrive shaft 15. The drive shaft 15 is rotatably mounted in a journalbearing 16 and is adapted to be driven by a conventional electric motor(not shown). A clutch mechanism 17 is mounted on the shaft 15 forselectively locking the shaft 15 to the drum 12 by driving the drum 12.All of the foregoing structure is conventional in large hoists, such asare used in mines.

The clutch mechanism 17 includes an annular clutch hub 18 fixed on theshaft 15. The clutch hub 18 includes a pair of diametrically extendingarms 19 carrying respective clutch jaws 20 slidably mounted on the arms19 for movement radially inward or outward thereon.

The drum 12 includes an internally toothed annular ring gear 24 fixedlymounted within the drum 12 and surrounding the clutch hub 18 adapted tobe engaged by the jaws 20 for locking the shaft 15 and drum 12 together.The jaws 20 have external teeth 25 for positively mating with the ringgear 24 for driving purposes.

The jaws 20 are moved on the arms 19 radially inwardly and outwardly bymeans of respective lever assemblies 26. Each lever assembly includes alever 28 having an end pivotally mounted on a pivot 30 located in anopening 32 formed in the clutch hub 18. Each lever assembly 26 furtherincludes a link 34 pivotally connected at one end to the middle of thelever 28 and at the other end to a jaw 20.

A gear plate 36 is rotatably mounted. in a peripherally extending groove38 formed in the hub 18 and containing a bushing 40. The gear plate isengaged by a pinion gear 42 which is driven through a conventionalmagnetic clutch 44 by a low r.p.m., high torque electric gear motor 46.

The gear plate 36 contains a pair of spinal or eccentric slots 48therein. Each slot has a first end 52 located radially closer to thecenter of gear plate 36 than the opposite end 54. Each of the levers 28has a ball joint 56 mounted on the end thereof by a threaded nut 58 andis slidably disposed in one of the slots 48. Thus, it will be observedthat as the gear plate 36 is rotated by the motor 46, the ball joints 56Will ride in the slots 48 and will thereby act as cam followers in theslots 48, the ball joints 56 being cammed radially inwardly or outwardlywith respect to the center of plate 36. As the ball joints 56 are somoved, the levers 28 are pivoted on their pivots 30 causing the links 34to move the jaws 20 radially within the arms 19.

It should be understood that in order for the jaws 20 to be cammed intodriving engagement with the ring gear 24, the drive shaft 15 is stopped,the magnetic clutch 44 is engaged and the gear motor 46 is energized todrive the pinion gear 42 causing the gear plate 36 to rotate. As thegear plate 36 is rotated counterclockwise (viewing FIG. 2) through anare determined by the length of the slots 48, the jaws are cammed intoengagement with the ring gear 24.

A limit switch 59 having a switch member 60 extending therefrom ismounted on the arm 19, the switch member 60 being in the line ofmovement of the lever 28. The limit switch 59 provides means forautomatically disengaging the magnetic clutch 44 when the jaws 20 are intheir outermost or drum-connecting position. When the switch member 60'is contacted by the lever 28, the switch 59 is opened. The switch 59 isconnected in the magnetic clutch circuit by conventional means, such ascontact rings mounted on the hub 18, so that opening the switch 59 willcause the magnetic clutch 44 to disengage.

At this time, the drive shaft 15 may be rotated in either clockwise orcounterclockwise direction, and the drum 12 will be driven by it. If thedrum is to be disconnected from its operative driving connection todrive shaft 15 by declutching of the clutch mechanism 10, it will benecessary to stop the drive shaft 15 and drum 12 and to electricallyenergize the magnetic clutch 44 and the motor 46 to rotate the gearplate 36 on the clutch hub 18.

It will be appreciated that the disconnection of the magnetic clutch 44may be effected manualiy as well as by use of the switch 59. Inaddition, the switch 59 must be bypassed by a conventional circuit forenergizing the magnetic clutch 44 to retract the jaws 29 from engagingor clutching positions with the ring gear 24. No attempt is made todisclose the specific circuits for the clutch 44 and the motor 46because such circuits can easily be designed by an electrical designer.

The elimination of the prior art sliding sleeve by this invention,enables the bearing 16 for the drive shaft 15 to be placed closer to theend of the drum 12, thus reduc ing the floor area occupied by the hoistand increasing the rigidity of the drive shaft 15. In addition, theeimination of the sliding sleeve eliminates the prior art wear problemsexisting between the sleeve and drive shaft.

Although only a single embodiment of the invention is described indetail, it will be understood that the invention is not limited simplyto this embodiment but contemplates other embodiments and variationswhich utilize the concepts and teachings of this invention.

Having described my invention, 1 claim:

1. A clutch mechanism for clutching a drive shaft to a drum comprising:

at least one radially extending arm on said drive shaft;

a jaw member slidably mounted in said arm for radial movement withrespect to the drive shaft;

means on said drum for receiving said jaw member in order to drivinglyconnect said drive shaft to said drum;

means for selectively connecting said jaw member to said receiving meanswhereby said drum will be rotatably driven by said drive shaft;

said connecting means including a peripheraliy toothed gear platejournalled on said drive shaft and having an arcuately extendingeccentric slot;

a cam follower operatively connected between said jaw member and saideccentric slot;

said cam follower having one end in said slot and being positioned formovement with respect to said gear plate, the other end of said carnfollower being pivoted to said drive shaft for radial movement as saidgear plate is rotated;

means for rotating said gear plate on said drive shaft whereby said camfollower will move said jaw member radially with respect to said drum;and

said rotating means including a prime mover having gear means thereonfor meshing with said gear plate.

2. The combination of claim 1 including:

linkage means connected between said cam follower and said jaw memberwhereby the pivotal movement of said cam follower causes radial slidingmovement of said jaw member.

3. The combination of claim 1 including:

clutch means for connecting said prime mover to said prime mover gearmeans; and

switch means positioned on said arm and in the path of said cam followerfor disconnecting said clutch means upon actuation of said switch meansby said cam follower.

References Cited UNITED STATES PATENTS 3/1876 Remington et al. l927l2/1934 Cramp l9271 6/1957 Dick l927l X 2/1963 Volker 19274 X

